Explosive Helical Tube Forming for Thin-Walled Cylinder Closures

Solution Overview

Problem

Current containers for radioactive materials are costly to produce and require specialized tools for closure, with bolted closures being vulnerable to damage and increasing operator radiation exposure during closure operations, which complicates compliance with safety regulations for transport and storage.

Innovation Solution

A tooling assembly and method for explosively forming helical tubes from thin-walled cylinders, allowing for the creation of a closure mechanism that enhances the container's ability to withstand regulatory tests while reducing production costs and improving safety and efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If standard bolted drum closure rings or welded fittings are used to close packagings, then adequate confinement of radioactive material is provided, but production cost increases and operator radiation exposure increases due to required specialized tools and time-consuming closure operations

Engineering Contradiction:

Improveconfinement integrityVSAvoidproduction cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces traditional mechanical closure systems (bolted rings, welded fittings) with an explosively formed integral closure mechanism. The explosive forming process creates permanent deformation features directly on the drum head that serve as self-contained closure elements, eliminating the need for separate fastening components and specialized tools.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The invention merges the drum body and closure mechanism into an integral structure. The explosive forming process creates closure features that are permanently attached to the drum head, eliminating the need for separate closure components and reducing assembly complexity.

Inventive Principle:

Principle #5Merging (Combining)

2Reliability

If standard bolted drum closure rings or welded fittings are used to close packagings, then adequate confinement of radioactive material is provided, but operator radiation exposure increases due to time-consuming closure operations requiring multiple fasteners and specialized tools

Engineering Contradiction:

Improveconfinement integrityVSAvoidclosure operation time

Core Design Contradiction:

ReliabilityVSLoss of time

Solution Approach 1:

The patent replaces traditional mechanical closure systems (bolted rings, welded fittings) with an explosively formed integral closure mechanism. The explosive forming process creates permanent deformation features directly on the drum head that serve as self-contained closure elements, eliminating the need for separate fastening components and specialized tools.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The closure features are formed during the manufacturing process itself, before the drum is put into service. The explosive forming creates pre-integrated closure mechanisms that require no field assembly or specialized tools during loading operations.

Inventive Principle:

Principle #10Preliminary action

3Reliability

If standard drum closure rings or bolted closures are used, then adequate confinement is achieved, but the closure components are vulnerable to damage that could release radioactive material

Engineering Contradiction:

Improveconfinement integrityVSAvoiddamage vulnerability

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention merges the drum body and closure mechanism into an integral structure. The explosive forming process creates closure features that are permanently attached to the drum head, eliminating the need for separate closure components and reducing assembly complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The explosive forming process creates simple, robust deformation features that are inherently resistant to damage. These integral features eliminate vulnerable moving parts such as bolts, nuts, and closure rings that could fail or become dislodged during transport accidents.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The method enables the production of helical tubes that perform better in tests such as free drop, penetration, and compression tests, reducing the risk of radioactive material leakage and operator exposure, while simplifying the closure process and reducing costs.

Implementation Method 1

positioning an explosive charge within the cavity. The method further includes detonating the explosive charge. As a result, the at least one thin-walled cylinder is formed into a helical tube

Methodology Applied

Scientific EffectExplosion: Explosion

Implementation Method 2

detonating the explosive charge. As a result, the at least one thin-walled cylinder is formed into a helical tube

Methodology Applied

Scientific EffectShock wave: Shock Wave

Data Source

PatentUS11628485B2Tooling assembly and method for explosively forming features in a thin-walled cylinder

Publication Date: 2023.04.18 BATTELLE SAVANNAH RIVER ALLIANCE LLC

AI summary

The present invention provides a method of explosively forming a helical tube from at least one thin-walled cylinder using a tooling assembly. The method includes inserting the at least one thin-walled cylinder into a die of the tooling assembly. The die surrounds the at least one thin-walled cylinder and includes an interior surface that defines a helical thread pattern. The method further includes surrounding the at least one thin-walled cylinder and the die with a casing of the tooling assembly. A cavity is defined by the casing and the thin-walled cylinder. The method further includes positioning an explosive charge within the cavity. The method additionally includes at least partially submerging the tooling assembly. The method further includes detonating the explosive charge. As a result, the at least one thin-walled cylinder is formed into a helical tube that corresponds with helical thread pattern of the interior surface of the die.